Secretary of State Mike Pompeo announced it in a press release that can be found here: https://www.state.gov/secretary/remarks/2018/12/288006.htm, with these words:
"In far too many places across the globe, individuals continue to face harassment, arrests, or even death for simply living their lives in accordance with their beliefs. The United States will not stand by as spectators in the face of such oppression. Protecting and promoting international religious freedom is a top foreign policy priority of the Trump Administration. In July, I hosted the first-ever Ministerial to Advance Religious Freedom, which brought together some 85 likeminded governments and more than 400 civil society organizations to harness global attention and motivate forceful action to advance respect for the human right of religious freedom."
Ambassador at Large for International Religious Freedom Sam Brownback, during his congressional testimony, explained why Russia was put on the list:
“Russia is trending in the wrong direction a series of things, arbitrary arrests and imprisonment particularly of Jehovah’s Witnesses that were banned, widespread suppression of religious expression and in practice they have a 2016 law criminalizing illegal missionary activities that have included 156 cases reported by NGO’s in 2017 starting with Salvation Army, Pentecostals, Jehovah Witnesses, of course, Baptists, the Administrative Center of the new Apostolic Church, the Presbyterian Church, the Lutheran Church, the Church of Jesus Christ of Latter Day Saints, Ukrainian Reform Orthodox Church, and the Russian Orthodox Church abroad, along with a series of Muslim groups and they banned the reading of the Turkish Islamic theologian Said Nursi. Under a distorted interpretation of its extremists laws they have 145 currently jailed prisoners for religious beliefs, 106 of which are Muslims, they particularly as well go after the Church of Scientology and those are the reasons we’re put them on the special watch list. Along with other regions as well that we could talk about.”
You can find a video of this testimony here: https://www.youtube.com/watch?v=Q6qc0uwKvRA, and the above excerpt can be listened to at 43:01.
"In far too many places across the globe, individuals continue to face harassment, arrests, or even death for simply living their lives in accordance with their beliefs. The United States will not stand by as spectators in the face of such oppression. Protecting and promoting international religious freedom is a top foreign policy priority of the Trump Administration. In July, I hosted the first-ever Ministerial to Advance Religious Freedom, which brought together some 85 likeminded governments and more than 400 civil society organizations to harness global attention and motivate forceful action to advance respect for the human right of religious freedom."
Ambassador at Large for International Religious Freedom Sam Brownback, during his congressional testimony, explained why Russia was put on the list:
“Russia is trending in the wrong direction a series of things, arbitrary arrests and imprisonment particularly of Jehovah’s Witnesses that were banned, widespread suppression of religious expression and in practice they have a 2016 law criminalizing illegal missionary activities that have included 156 cases reported by NGO’s in 2017 starting with Salvation Army, Pentecostals, Jehovah Witnesses, of course, Baptists, the Administrative Center of the new Apostolic Church, the Presbyterian Church, the Lutheran Church, the Church of Jesus Christ of Latter Day Saints, Ukrainian Reform Orthodox Church, and the Russian Orthodox Church abroad, along with a series of Muslim groups and they banned the reading of the Turkish Islamic theologian Said Nursi. Under a distorted interpretation of its extremists laws they have 145 currently jailed prisoners for religious beliefs, 106 of which are Muslims, they particularly as well go after the Church of Scientology and those are the reasons we’re put them on the special watch list. Along with other regions as well that we could talk about.”
You can find a video of this testimony here: https://www.youtube.com/watch?v=Q6qc0uwKvRA, and the above excerpt can be listened to at 43:01.